Power conversion is used to regulate and distribute electricity—whether in megawatts transmitted along high-voltage power lines or nanoamps driven through the logic gates of a computer. The power conversion units, used to step one voltage or phase to another, to invert AC to DC, or to isolate a supply line, rely on electronic switches for their operation. The ideal switch oscillates between an on-state with near-zero resistance to current flow and an off-state approaching infinite resistance for a range of switching frequencies.